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Question 94 of 100
Error Handling & Debugging
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Q94: How Do You Test API Retry Mechanisms in case of Failure?
🔁Core Concept
How Do You Test API Retry Mechanisms in case of Failure?
Key Takeaways & Architecture Summary
- ✓Simulate network failures or server errors (503) using mock stubs.
- ✓Verify that the client retries the request according to the retry policy.
- ✓Confirm that retry schedules incorporate exponential backoff delays.
Direct Answer Summary
Testing retry mechanisms involves using mock engines (like WireMock) to simulate network failures or HTTP 503 errors. You assert that the client application retries the call according to your retry configuration, incorporating exponential backoff delays to prevent overloading the server.
⚠️ Senior Engineering Warning (Red Flag)
Avoid retrying non-idempotent operations like POST requests. If you retry a failed POST request, the server may end up executing the creation action twice, corrupting database states.
💡 STAR Architectural Explanation & Pro Tip
Robust retry policies incorporate Jitter (randomized delays) alongside exponential backoff. This prevents all failing clients from retrying at the exact same second, avoiding server overload.
PlaywrightApiTest.ts
Playwright API// Playwright custom API retry configuration
const response = await apiContext.get('/api/v1/jobs', {
// Retries requests up to 3 times on connection failure
maxRetries: 3
});